Along with the rapid development of the three-dimensional (3D) display technology, the demand for a 3D display device is growing. Among various technologies for 3D display, an autostereoscopic display technology has attracted more and more attentions because it is unnecessary for a viewer to use spectacles.
Currently, as a primary mode for the autostereoscopic display technology, a grating is arranged in front of a display panel, and a pixel units of the display panel are divided into pixels in odd-numbered rows and pixels in even-numbered rows in a horizontal direction. As a result, it is able to provide a left eye and a right eye of the viewer with different images and generate depth information on the basis of a parallax effect between a left-eye image and a right-eye image of the viewer, thereby to provide a stereo display effect.
As shown in FIGS. 1 and 2, an existing liquid crystal grating includes a first substrate 1 and a second substrate 2 arranged opposite to each other, and a first electrode 3, a liquid crystal layer 4 and a second electrode 5 arranged sequentially between the first substrate 1 and the second substrate 2. The first electrode 3 consists of a plurality of bar-like electrodes arranged in an array form, and the second electrode 5 is a planar electrode. Liquid crystal molecules in the liquid crystal layer 4 are deflected due to a voltage difference between the first electrode 3 and the second electrode 5, so as to form a specific arrangement mode for the liquid crystal molecules.
When the voltage difference between the first electrode 3 and the second electrode 5 is less than a threshold value, as shown in FIG. 1, the liquid crystal molecules in the liquid crystal layer 4 are in an initial state where they are not deflected, and light beams from the display panel can pass through the liquid crystal grating, so as to achieve the 2D display. When the voltage difference between the first electrode 3 and the second electrode 5 is greater than the threshold value, as shown in FIG. 2, the liquid crystal molecules at a region corresponding to the first electrode 3 are deflected to be in an upright state where the light beams from the display panel cannot pass therethrough, while the liquid crystal molecules at a position other than the region corresponding to the first electrode 3 are not deflected and the light beams from the display panel can pass therethrough. As a result, it is able to deflect the light beams for the left-eye image and the right-eye image toward the viewer's left eye and right eye, respectively, thereby to achieve the 3D display.
When a 3D image is viewed by the viewer in both a landscape orientation and a portrait orientation, slits of the grating are required to be located at variable positions. However, in the existing liquid crystal grating, the slits are located at fixed positions, and the 3D image can merely be viewed in one orientation. Hence, there is an urgent need in the art to develop a liquid crystal grating with adjustable slit positions, so as to enable the viewer to view the 3D image in both the landscape orientation and the portrait orientation.